Dopa-responsive dystonia (DRD) starts in childhood with trouble walking, spasticity and later development of parkinsonism, and diurnal fluctuation of symptoms. Intellectual, cerebellar, sensory, or autonomic disturbances do not occur. Two types are dominant and another is autosomal recessive. Mutations in the GCH1 gene coding for the enzyme GTPCH1 can cause autosomal dominant DRD, and mutations in the TH gene coding for the enzyme TH can cause autosomal recessive DRD.